Integrated circuit package and method of forming the same

ABSTRACT

Aspects of the invention are directed towards an integrated circuit package and method of forming the same, and more particularly to a redistributed chip packaging for an integrated circuit. The integrated circuit package includes an integrated circuit having a protective material on at least a portion of the integrated circuit. A lead frame is coupled to the integrated circuit and a conductive layer is also coupled to the interconnect. A solder ball is coupled to the conductive layer and a passivation layer is on the conductive layer. Active and passive components are electrically coupled to the integrated circuit.

This application claims the benefit of U.S. Provisional PatentApplication No. 61/147,430, filed on Jan. 26, 2009, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an integrated circuit package and method offorming the same, and more particularly to a redistributed chippackaging for an integrated circuit.

2. Discussion of the Related Art

With continuously decreasing semiconductor device dimensions andincreasing device packaging densities, the packaging of semiconductordevices has continued to gain in importance. In the electronicsindustry, the continuing goal has been to reduce the size of electronicdevices such as in digital cameras and camcorders. Metal interconnects,thereby including points of metal contact solder bumps that connect asemiconductor to surrounding circuits, increasingly become important.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an integrated circuitpackage and method of forming the same that substantially obviates oneor more of the problems due to limitations and disadvantages of therelated art.

An advantage of an embodiment of the invention is to provide reducedprocessing steps for foaming a chip packing.

Another advantage of an embodiment of the invention is to provide areduced cost of forming a chip packing.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the invention, an embodiment of the invention is directed towards anintegrated circuit package. The integrated circuit package includes anintegrated circuit having a protective material on at least a portion ofthe integrated circuit. A lead frame is coupled to the integratedcircuit and a conductive layer is also coupled to the interconnect. Asolder ball is coupled to the conductive layer and a passivation layeris on the conductive layer. Active and passive components areelectrically coupled to the integrated circuit.

In another aspect, an embodiment of the invention is directed towards amethod of forming an integrated circuit package. The method includesforming a lead frame including a first portion and a second portion. Thefirst portion and the second portion of the lead frame intersect at anangle ranging from about 45 degrees to about 135 degrees. An adhesivematerial is formed on the first portion of the lead frame and a carrieris attached to the lead frame with the adhesive material. An integratedcircuit is also attached to the adhesive material. Interconnects areformed on the integrated circuit and protective material is formed onthe integrated circuit.

In another aspect, an embodiment of the invention is directed towards amethod of making an integrated circuit package. The method includesforming a lead frame including a first portion and a second portion. Thefirst portion and the second portion of the lead frame intersect at anangle ranging from about 45 degrees to about 135 degrees. A double sidedthermal tape is adhered to a bottom surface of the first portion of thelead frame; attaching a carrier to the lead frame with the thermaldouble-sided thermal tape is also part of the method. The method furtherincludes attaching an integrated circuit to the thermal double-sidedadhesive tape adjacent to the first portion of the lead frame andforming at least one pillar interconnect on the integrated circuit. Acompressive compound is formed over the integrated circuit as well asover the first and second portions of the lead frame. The compressivecompound is hardened by heating the compressive compound to atemperature in the range of about 120° C. to about 150° C.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1A illustrates a cross-sectional view of manufacturing a lead frameof the integrated circuit package of FIG. 1 according to an embodimentof the invention;

FIG. 1B illustrates a top-down view of the lead frame in FIG. 1A;

FIG. 2 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package of FIG. 1;

FIG. 3 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package of FIG. 1;

FIG. 4 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package of FIG. 1;

FIG. 5 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package of FIG. 1; and

FIG. 6 illustrates a completed integrated circuit package.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to an embodiment of the presentinvention, an example of which is illustrated in the accompanyingdrawings.

FIG. 1A illustrates a cross-sectional view of manufacturing anintegrated circuit package according to an embodiment of the invention.

FIG. 1A illustrates forming a lead frame 100 having a first portion 102and a second portion 104. The first portion 102 and the second portion104 intersect forming an angle 106 ranging from about 45 degrees toabout 135 degrees. In a preferred embodiment, the angle ranges fromabout 85 degrees to about 95 degrees. In a more preferred embodiment,the angle is about 90 degrees. The lead frame 100 comprises a conductivematerial. The conductive material may be a single material or an alloymaterial such as aluminum, gold, copper, combinations thereof, and thelike. Now referring to FIG. 1B, it shows a top-down view of the leadframe 100. The lead frame is manufactured by forming the conductivematerial via stamping or etching as known in the art. In a preferredembodiment, the conductive material is stamped to form a plurality ofopen spaces 108 and bent into the desired angle 106 as shown in FIG. 1A.

FIG. 2 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package after forming the leadframe.

Referring to FIG. 2, an adhesive material 202 is formed on the bottomportion of the lead frame 100. In a preferred embodiment, the adhesivematerial 202 is double-sided thermal release tape such as 3195V by NittoDenko, Japan. The double-sided thermal release tape is capable of beingremoved after thermo process at a high temperature ranging from about175° C. to about 260° C. The adhesive material 202 is attached to abottom surface of the lead frame and/or a carrier 204; next the carrier204 is attached to an opposite surface of the adhesive material 202. Thecarrier 204 is for transportation of the apparatus and may includematerials such as plastics, glass (e.g., low temperature CT glass),ceramics, steel, combinations thereof, and the like.

An integrated circuit chip 206 is attached to the adhesive material 202.The integrated circuit chip 206 is arranged between second portions 104of the lead frame 100. At least one interconnect 208 is formed on theintegrated circuit chip 206. In a preferred embodiment, the interconnect208 includes a conductive material, e.g., copper, gold, pewter,combinations thereof, and the like, formed by plating as known in theart. In a preferred embodiment, the interconnect is a copper pillarbump. Of course, other conductive materials may also be used, such asalloys and the like.

FIG. 3 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package after attaching a carrier.

Referring to FIG. 3, a protective material 302 is formed over thestructure in FIG. 2. The protective material is an encapsulant ofmaterial such as epoxy, plastic, polymers, combinations thereof, and thelike. In a preferred embodiment, the protective material is an epoxycompressive molding compound. The protective material may either come inpowder or liquid form. If in powder form, the powder needs to beprocessed before applying. The compressive molding compound is capableof being hardened during a molding process. In this embodiment, a mold(not shown) is affixed from the top and bottom and heated for thedesired time and to the desired temperature to harden the protectivematerial. After which, the mold is released, thereby forming a hardenedprotective material 302.

In a preferred embodiment, the hardening process includes heating thecompound to a temperature ranging from about 120° C. to about 150° C.for a time ranging from about 2 to about 10 minutes. Also, in thepreferred embodiment, the epoxy part is R4212 epoxy molding compoundfrom Nagase Corp. of Japan.

FIG. 4 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package after forming thecompressive molding compound.

Referring to FIG. 4, the adhesive material 202 and carrier 204 areremoved by heating the apparatus to a thermal release temperature, e.g.,a temperature ranging from about 175° C. to about 260° C. In a preferredembodiment, the apparatus is heated to a temperature of about 260° C.

FIG. 5 illustrates a cross-sectional view of an intermediate stage ofmanufacturing the integrated circuit package after forming thecompressive molding compound.

Referring to FIG. 5, an upper and lower portion of the compressivemolding compound 302 is removed. Removing these portions may beaccomplished with grinding and/or polishing procedures as known in theart such as wheel silicon grinding. In a preferred embodiment, thecompressive molding on the lower surface is grinded to remove the secondportion 104 of the lead frame 100, e.g., about 115 μm of the secondportion 104. The upper surface of the compressive molding compound 302is removed to expose a surface of the interconnect 208 and the firstportion 102 of the lead frame 100.

FIG. 6 illustrates a completed integrated circuit package.

Referring to FIG. 6, a first metallization layer is formed on a firstsurface of the compressive molding 302. A second metallization layer isformed on a second surface of the compressive molding 302. The first andsecond metallization layers are formed of conductive material to athickness ranging from about 3 μm to about 10 μM via chemical vapordeposition, physical vapor deposition, and the like. The firstmetallization layer is etched to form interconnect traces 602. Thesecond metallization layer is etched to form interconnect traces 604.The first and second metallization layers may be faulted of differentmaterials. In a preferred embodiment, the first and second metallizationlayers consist of copper, aluminum, gold, or alloys thereof.

A first passivation layer 606 is formed on the interconnect traces 602and a second passivation layer 608 is formed on the interconnect traces604. The first passivation layer 606 is etched to form a contact hole610. The first and second passivation layers are formed of insulativematerial via polymers, e.g., photosensitive liquid polymers. Theinsulating materials may include parylene, polyimide, benzocyclobutene(BCB), polybenzoxazole. (PBO), combinations thereof, and the like. Thefirst and second passivation layers may be formed of differentmaterials. A solder ball 612 is formed in the contact hole 610. Thesolder ball 612 is formed from conventional processes and may include aconductive material, such as silver, copper, tin, combinations thereof,and the like. Components 614, such as passive or active componentsincluding, for example, capacitors, resistors, transistors, inductors,combinations thereof, and the like, are attached to the interconnecttraces 604.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. An integrated circuit package, comprising: an integrated circuit; aprotective material on at least a portion of the integrated circuit; alead frame coupled to the integrated circuit; a conductive layer coupledto the interconnect; a solder ball coupled the conductive layer; and apassivation layer on the conductive layer.
 2. The integrated circuitpackage of claim 1, wherein the protective material comprises acompressive molding compound.
 3. The integrated circuit package of claim2, wherein the compressive molding compound comprises epoxy.
 4. Theintegrated circuit package of claim 1, wherein the lead frame comprisesa material selected from the group consisting of Al, Au, Cu, andcombinations thereof.
 5. The integrated circuit package of claim 1,wherein the passivation layer comprises an insulating polymer selectedfrom the group consisting of parylene, polyimide, benzocyclobutene(BCB), and polybenzoxazole (PBO).
 6. The integrated circuit package ofclaim 1, wherein the lead frame comprises a conductive material selectedfrom the group consisting of Au, Al, Cu, Ti, and alloys of the same. 7.The integrated circuit package of claim 1, further comprising at leastone of active and passive components electrically coupled to theintegrated circuit.
 8. A method of forming an integrated circuitpackage, comprising the steps of: forming a lead frame comprising afirst portion and a second portion, wherein the first portion and thesecond portion intersect at an angle ranging from about 45 degrees toabout 135 degrees; forming an adhesive material on the first portion ofthe lead frame; attaching a carrier to the lead frame with the adhesivematerial; attaching an integrated circuit to the adhesive material;forming an interconnect on the integrated circuit; and forming aprotective material on the integrated circuit.
 9. The method of claim 8,wherein the angle is in the range from about 85 degrees to about 95degrees.
 10. The method of claim 8, wherein forming the protective layercomprises the step of: heating an epoxy material to a temperature in therange from about 120° C. to about 150° C. to harden the epoxy material.11. The method of claim 8, further comprising removing the carrier andthe adhesive material by heating an epoxy material to a temperature fromabout 175° C. to about 260° C. to thermally release the adhesivematerial and carrier.
 12. The method of claim 11, further comprising thesteps: removing a portion of the hardened epoxy material to expose theinterconnect and the first portion of the lead frame; and removing thesecond portion of the lead frame.
 13. The method of claim 12, whereinremoving the portion of hardened epoxy material comprises grinding anupper surface of the hardened compound.
 14. The method of claim 12,further comprising the steps of: forming a conductive material on thehardened compound; forming a passivation layer on the conductivematerial; and faulting a solder ball on the passivation layer, whereinthe solder ball is electrically coupled to the conductive material. 15.A method of making an integrated circuit package, comprising the stepsof: forming a lead frame comprising a first portion and a secondportion, wherein the first portion and the second portion intersect atan angle ranging from about 45 degrees to about 135 degrees; adhering adouble-sided thermal tape to a bottom surface of the first portion ofthe lead frame; attaching a carrier to the lead frame with thedouble-sided thermal tape; attaching an integrated circuit to thedouble-sided thermal adhesive tape adjacent to the first portion of thelead frame; forming at least one pillar interconnect on the integratedcircuit; forming a compressive compound over the integrated circuit andthe first and second portions of the lead frame; and hardening thecompressive compound by heating the compressive compound to atemperature in the range from about 120° C. to about 150° C.
 16. Themethod of claim 15, further comprising the steps: removing a portion ofthe hardened molding to expose the pillar interconnect and the secondportion of the lead frame; and removing the first portion of the leadframe.
 17. The method of claim 16, wherein the removing the portion ofcompressive molding step comprises grinding an upper surface of thecompressive molding.
 18. The method of claim 17, further comprising thesteps of: forming a conductive material on the hardened molding; forminga first passivation layer on an upper surface of the conductivematerial; forming a second passivation layer on a lower surface of thecompressive molding material; and forming a solder ball on the firstpassivation layer, wherein the solder ball is electrically coupled tothe conductive material.
 19. The method of claim 15, wherein thecompressive molding material comprises an epoxy material.
 20. The methodof claim 18, further comprising the steps of attaching a component tothe lower surface of the compressive molding.